From 9824dfae5741275473a23a7ed5756c7b6efacc9d Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Wed, 12 Sep 2018 07:36:35 +0200 Subject: [PATCH] net/appletalk: fix minor pointer leak to userspace in SIOCFINDIPDDPRT Fields ->dev and ->next of struct ipddp_route may be copied to userspace on the SIOCFINDIPDDPRT ioctl. This is only accessible to CAP_NET_ADMIN though. Let's manually copy the relevant fields instead of using memcpy(). BugLink: http://blog.infosectcbr.com.au/2018/09/linux-kernel-infoleaks.html Cc: Jann Horn Signed-off-by: Willy Tarreau Signed-off-by: David S. Miller --- drivers/net/appletalk/ipddp.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/appletalk/ipddp.c b/drivers/net/appletalk/ipddp.c index 9375cef22420..3d27616d9c85 100644 --- a/drivers/net/appletalk/ipddp.c +++ b/drivers/net/appletalk/ipddp.c @@ -283,8 +283,12 @@ static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) case SIOCFINDIPDDPRT: spin_lock_bh(&ipddp_route_lock); rp = __ipddp_find_route(&rcp); - if (rp) - memcpy(&rcp2, rp, sizeof(rcp2)); + if (rp) { + memset(&rcp2, 0, sizeof(rcp2)); + rcp2.ip = rp->ip; + rcp2.at = rp->at; + rcp2.flags = rp->flags; + } spin_unlock_bh(&ipddp_route_lock); if (rp) { -- 2.30.2